The text to speech in Firefox Developer edition doesn't work properly

I moved from firefox to the Developer edition. For a few years now, whenever want to read long text, I highlight it and let my mac read it for me.

In firefox works great. In the developer edition, it’s not so great. It also reads punctuations, stops when it comes to links, if I mistakenly change tabs it stops reading (which is the most annoying thing)

Is there a setting I can change to fix this issue?

I think you are referring to a Mac OS feature or other external screen reader, rather than the built-in Reader view’s Narrate feature or an add-on?

If you open the about:config pages in both regular and DE and use the checkbox for filter for modified preferences, do you see any starting with accessibility that are different between the two? Not sure whether other preferences would be relevant…